Distributed queueing in a remote network management architecture

ABSTRACT

An embodiment may involve proxy server applications within a managed network, and a computational instance disposed within a remote network management platform. The computational instance may contain queues and facilitate the execution of applications. Communication between the computational instance and managed network may involve: (i) selecting, by a particular application, a particular output queue; (ii) writing, by the particular application, a unit of work generated by the particular application to the particular output queue; (iii) retrieving, by a particular proxy server application, the unit of work; (iv) carrying out, by the particular proxy server application, the unit of work; (v) writing, by the particular proxy server application, a result to a particular input queue, where the result represents an outcome of carrying out the unit of work; and (vi) retrieving, by the particular application, the result from the particular input queue.

BACKGROUND

Remote management of networks may involve a remote network managementplatform gathering information regarding the configuration andoperational aspects of a managed network, and making this informationavailable by way of a web-based graphical user interface. Through use ofthe graphical user interface these aspects of the managed network may beviewed, and possibly changed. Further, the remote network managementplatform may facilitate the design and implementation of workflows forprocesses and operations used by the managed network.

In order to enable these features, the remote network managementplatform communicates with the managed network. Several implementationsof this communication may be possible. However, many of theseimplementations are complex to configure, or suffer from bottlenecksand/or duplicated effort that negatively impact performance.

SUMMARY

The embodiments herein introduce the use of multiple queues forcommunication between a remote network management platform and a managednetwork. Each queue may be dedicated to a particular application or apriority of traffic, for example. This architecture facilitates a moreflexible configuration that can be tuned to the performance needs of thesystem. In some cases, a proxy queue in the managed network enablesanalysis of results prior to these results being placed in one or moreof the multiple queues for delivery to the remote network managementplatform. The proxy queue can be scanned for opportunities to removeduplicated results, split large result entries into smaller chunks,and/or perform other beneficial operations.

Accordingly, a first example embodiment may involve a plurality of proxyserver applications disposed within a managed network and acomputational instance disposed within a remote network managementplatform. The remote network management platform may manage the managednetwork by way of the computational instance. The computational instancemay contain a plurality of queues and facilitate the execution of aplurality of applications. Each of the plurality of applications may beconfigured to communicate with one or more of the proxy serverapplications by way of one or more of the plurality of queues. Thiscommunication may involve operations of: (i) selecting, by a particularapplication of the plurality of applications, a particular output queueof the plurality of queues, (ii) writing, by the particular application,a unit of work generated by the particular application to the particularoutput queue, (iii) retrieving, by a particular proxy server applicationof the plurality of proxy server applications, the unit of work from theparticular output queue, (iv) carrying out, by the particular proxyserver application, the unit of work, (v) writing, by the particularproxy server application, a result to a particular input queue of theplurality of queues, where the result represents an outcome of carryingout the unit of work, and where the particular input queue is associatedwith the particular output queue, and (vi) retrieving, by the particularapplication, the result from the particular input queue.

In a second example embodiment, an article of manufacture may include anon-transitory computer-readable medium, having stored thereon programinstructions that, upon execution by a computing system, cause thecomputing system to perform operations in accordance with the firstexample embodiment.

In a third example embodiment, a computing system may include at leastone processor, as well as memory and program instructions. The programinstructions may be stored in the memory, and upon execution by the atleast one processor, cause the computing system to perform operations inaccordance with the first example embodiment.

In a fourth example embodiment, a system may include various means forcarrying out each of the operations of the first example embodiment.

These as well as other embodiments, aspects, advantages, andalternatives will become apparent to those of ordinary skill in the artby reading the following detailed description, with reference whereappropriate to the accompanying drawings. Further, this summary andother descriptions and figures provided herein are intended toillustrate embodiments by way of example only and, as such, thatnumerous variations are possible. For instance, structural elements andprocess steps can be rearranged, combined, distributed, eliminated, orotherwise changed, while remaining within the scope of the embodimentsas claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic drawing of a computing device, inaccordance with example embodiments.

FIG. 2 illustrates a schematic drawing of a server device cluster, inaccordance with example embodiments.

FIG. 3 depicts a remote network management architecture, in accordancewith example embodiments.

FIG. 4 depicts a communication environment involving a remote networkmanagement architecture, in accordance with example embodiments.

FIG. 5A depicts another communication environment involving a remotenetwork management architecture, in accordance with example embodiments.

FIG. 5B is a flow chart, in accordance with example embodiments.

FIG. 6A depicts queuing in a remote network management platform, inaccordance with example embodiments.

FIG. 6B depicts a user interface displaying content of a queued unit ofwork, in accordance with example embodiments.

FIG. 6C depicts a user interface displaying content of a result, inaccordance with example embodiments.

FIG. 7A depicts a queuing arrangement for a remote network managementarchitecture, in accordance with example embodiments.

FIG. 7B depicts a queuing arrangement for a remote network managementarchitecture, in accordance with example embodiments.

FIG. 7C depicts a queuing arrangement for a remote network managementarchitecture, in accordance with example embodiments.

FIG. 7D depicts a queuing arrangement for a remote network managementarchitecture, in accordance with example embodiments.

FIG. 7E depicts a queuing arrangement for a remote network managementarchitecture, in accordance with example embodiments.

FIG. 8 is a flow chart, in accordance with example embodiments.

DETAILED DESCRIPTION

Example methods, devices, and systems are described herein. It should beunderstood that the words “example” and “exemplary” are used herein tomean “serving as an example, instance, or illustration.” Any embodimentor feature described herein as being an “example” or “exemplary” is notnecessarily to be construed as preferred or advantageous over otherembodiments or features unless stated as such. Thus, other embodimentscan be utilized and other changes can be made without departing from thescope of the subject matter presented herein.

Accordingly, the example embodiments described herein are not meant tobe limiting. It will be readily understood that the aspects of thepresent disclosure, as generally described herein, and illustrated inthe figures, can be arranged, substituted, combined, separated, anddesigned in a wide variety of different configurations. For example, theseparation of features into “client” and “server” components may occurin a number of ways.

Further, unless context suggests otherwise, the features illustrated ineach of the figures may be used in combination with one another. Thus,the figures should be generally viewed as component aspects of one ormore overall embodiments, with the understanding that not allillustrated features are necessary for each embodiment.

Additionally, any enumeration of elements, blocks, or steps in thisspecification or the claims is for purposes of clarity. Thus, suchenumeration should not be interpreted to require or imply that theseelements, blocks, or steps adhere to a particular arrangement or arecarried out in a particular order.

I. INTRODUCTION

A large enterprise is a complex entity with many interrelatedoperations. Some of these are found across the enterprise, such as humanresources (HR), supply chain, information technology (IT), and finance.However, each enterprise also has its own unique operations that provideessential capabilities and/or create competitive advantages.

To support widely-implemented operations, enterprises typically useoff-the-shelf software applications, such as customer relationshipmanagement (CRM) and human capital management (HCM) packages. However,they may also need custom software applications to meet their own uniquerequirements. A large enterprise often has dozens or hundreds of thesecustom software applications. Nonetheless, the advantages provided bythe embodiments herein are not limited to large enterprises and may beapplicable to an enterprise, or any other type of organization, of anysize.

Many such software applications are developed by individual departmentswithin the enterprise. These range from simple spreadsheets tocustom-built software tools and databases. But the proliferation ofsiloed custom software applications has numerous disadvantages. Itnegatively impacts an enterprise's ability to run and grow its business,innovate, and meet regulatory requirements. The enterprise may find itdifficult to integrate, streamline and enhance its operations due tolack of a single system that unifies its subsystems and data.

To efficiently create custom applications, enterprises would benefitfrom a remotely-hosted application platform that eliminates unnecessarydevelopment complexity. The goal of such a platform would be to reducetime-consuming, repetitive application development tasks so thatsoftware engineers and individuals in other roles can focus ondeveloping unique, high-value features.

In order to achieve this goal, the concept of Application Platform as aService (aPaaS) is introduced, to intelligently automate workflowsthroughout the enterprise. An aPaaS system is hosted remotely from theenterprise, but may access data, applications, and services within theenterprise by way of secure connections. Such an aPaaS system may have anumber of advantageous capabilities and characteristics. Theseadvantages and characteristics may be able to improve the enterprise'soperations and workflow for IT, HR, CRM, customer service, applicationdevelopment, and security.

The aPaaS system may support development and execution ofmodel-view-controller (MVC) applications. MVC applications divide theirfunctionality into three interconnected parts (model, view, andcontroller) in order to isolate representations of information from themanner in which the information is presented to the user, therebyallowing for efficient code reuse and parallel development. Theseapplications may be web-based, and offer create, read, update, delete(CRUD) capabilities. This allows new applications to be built on acommon application infrastructure.

The aPaaS system may support standardized application components, suchas a standardized set of widgets for graphical user interface (GUI)development. In this way, applications built using the aPaaS system havea common look and feel. Other software components and modules may bestandardized as well. In some cases, this look and feel can be brandedor skinned with an enterprise's custom logos and/or color schemes.

The aPaaS system may support the ability to configure the behavior ofapplications using metadata. This allows application behaviors to berapidly adapted to meet specific needs. Such an approach reducesdevelopment time and increases flexibility. Further, the aPaaS systemmay support GUI tools that facilitate metadata creation and management,thus reducing errors in the metadata.

The aPaaS system may support clearly-defined interfaces betweenapplications, so that software developers can avoid unwantedinter-application dependencies. Thus, the aPaaS system may implement aservice layer in which persistent state information and other data isstored.

The aPaaS system may support a rich set of integration features so thatthe applications thereon can interact with legacy applications andthird-party applications. For instance, the aPaaS system may support acustom employee-onboarding system that integrates with legacy HR, IT,and accounting systems.

The aPaaS system may support enterprise-grade security. Furthermore,since the aPaaS system may be remotely hosted, it should also utilizesecurity procedures when it interacts with systems in the enterprise orthird-party networks and services hosted outside of the enterprise. Forexample, the aPaaS system may be configured to share data amongst theenterprise and other parties to detect and identify common securitythreats.

Other features, functionality, and advantages of an aPaaS system mayexist. This description is for purpose of example and is not intended tobe limiting.

As an example of the aPaaS development process, a software developer maybe tasked to create a new application using the aPaaS system. First, thedeveloper may define the data model, which specifies the types of datathat the application uses and the relationships therebetween. Then, viaa GUI of the aPaaS system, the developer enters (e.g., uploads) the datamodel. The aPaaS system automatically creates all of the correspondingdatabase tables, fields, and relationships, which can then be accessedvia an object-oriented services layer.

In addition, the aPaaS system can also build a fully-functional MVCapplication with client-side interfaces and server-side CRUD logic. Thisgenerated application may serve as the basis of further development forthe user. Advantageously, the developer does not have to spend a largeamount of time on basic application functionality. Further, since theapplication may be web-based, it can be accessed from anyInternet-enabled client device. Alternatively or additionally, a localcopy of the application may be able to be accessed, for instance, whenInternet service is not available.

The aPaaS system may also support a rich set of pre-definedfunctionality that can be added to applications. These features includesupport for searching, email, templating, workflow design, reporting,analytics, social media, scripting, mobile-friendly output, andcustomized GUIs.

The following embodiments describe architectural and functional aspectsof example aPaaS systems, as well as the features and advantagesthereof.

II. EXAMPLE COMPUTING DEVICES AND CLOUD-BASED COMPUTING ENVIRONMENTS

FIG. 1 is a simplified block diagram exemplifying a computing device100, illustrating some of the components that could be included in acomputing device arranged to operate in accordance with the embodimentsherein. Computing device 100 could be a client device (e.g., a deviceactively operated by a user), a server device (e.g., a device thatprovides computational services to client devices), or some other typeof computational platform. Some server devices may operate as clientdevices from time to time in order to perform particular operations, andsome client devices may incorporate server features.

In this example, computing device 100 includes processor 102, memory104, network interface 106, and an input/output unit 108, all of whichmay be coupled by a system bus 110 or a similar mechanism. In someembodiments, computing device 100 may include other components and/orperipheral devices (e.g., detachable storage, printers, and so on).

Processor 102 may be one or more of any type of computer processingelement, such as a central processing unit (CPU), a co-processor (e.g.,a mathematics, graphics, or encryption co-processor), a digital signalprocessor (DSP), a network processor, and/or a form of integratedcircuit or controller that performs processor operations. In some cases,processor 102 may be one or more single-core processors. In other cases,processor 102 may be one or more multi-core processors with multipleindependent processing units. Processor 102 may also include registermemory for temporarily storing instructions being executed and relateddata, as well as cache memory for temporarily storing recently-usedinstructions and data.

Memory 104 may be any form of computer-usable memory, including but notlimited to random access memory (RAM), read-only memory (ROM), andnon-volatile memory (e.g., flash memory, hard disk drives, solid statedrives, compact discs (CDs), digital video discs (DVDs), and/or tapestorage). Thus, memory 104 represents both main memory units, as well aslong-term storage. Other types of memory may include biological memory.

Memory 104 may store program instructions and/or data on which programinstructions may operate. By way of example, memory 104 may store theseprogram instructions on a non-transitory, computer-readable medium, suchthat the instructions are executable by processor 102 to carry out anyof the methods, processes, or operations disclosed in this specificationor the accompanying drawings.

As shown in FIG. 1, memory 104 may include firmware 104A, kernel 104B,and/or applications 104C. Firmware 104A may be program code used to bootor otherwise initiate some or all of computing device 100. Kernel 104Bmay be an operating system, including modules for memory management,scheduling and management of processes, input/output, and communication.Kernel 104B may also include device drivers that allow the operatingsystem to communicate with the hardware modules (e.g., memory units,networking interfaces, ports, and busses), of computing device 100.Applications 104C may be one or more user-space software programs, suchas web browsers or email clients, as well as any software libraries usedby these programs. Memory 104 may also store data used by these andother programs and applications.

Network interface 106 may take the form of one or more wirelineinterfaces, such as Ethernet (e.g., Fast Ethernet, Gigabit Ethernet, andso on). Network interface 106 may also support communication over one ormore non-Ethernet media, such as coaxial cables or power lines, or overwide-area media, such as Synchronous Optical Networking (SONET) ordigital subscriber line (DSL) technologies. Network interface 106 mayadditionally take the form of one or more wireless interfaces, such asIEEE 802.11 (Wifi), BLUETOOTH®, global positioning system (GPS), or awide-area wireless interface. However, other forms of physical layerinterfaces and other types of standard or proprietary communicationprotocols may be used over network interface 106. Furthermore, networkinterface 106 may comprise multiple physical interfaces. For instance,some embodiments of computing device 100 may include Ethernet,BLUETOOTH®, and Wifi interfaces.

Input/output unit 108 may facilitate user and peripheral deviceinteraction with example computing device 100. Input/output unit 108 mayinclude one or more types of input devices, such as a keyboard, a mouse,a touch screen, and so on. Similarly, input/output unit 108 may includeone or more types of output devices, such as a screen, monitor, printer,and/or one or more light emitting diodes (LEDs). Additionally oralternatively, computing device 100 may communicate with other devicesusing a universal serial bus (USB) or high-definition multimediainterface (HDMI) port interface, for example.

In some embodiments, one or more instances of computing device 100 maybe deployed to support an aPaaS architecture. The exact physicallocation, connectivity, and configuration of these computing devices maybe unknown and/or unimportant to client devices. Accordingly, thecomputing devices may be referred to as “cloud-based” devices that maybe housed at various remote data center locations.

FIG. 2 depicts a cloud-based server cluster 200 in accordance withexample embodiments. In FIG. 2, operations of a computing device (e.g.,computing device 100) may be distributed between server devices 202,data storage 204, and routers 206, all of which may be connected bylocal cluster network 208. The number of server devices 202, datastorages 204, and routers 206 in server cluster 200 may depend on thecomputing task(s) and/or applications assigned to server cluster 200.

For example, server devices 202 can be configured to perform variouscomputing tasks of computing device 100. Thus, computing tasks can bedistributed among one or more of server devices 202. To the extent thatthese computing tasks can be performed in parallel, such a distributionof tasks may reduce the total time to complete these tasks and return aresult. For purpose of simplicity, both server cluster 200 andindividual server devices 202 may be referred to as a “server device.”This nomenclature should be understood to imply that one or moredistinct server devices, data storage devices, and cluster routers maybe involved in server device operations.

Data storage 204 may be data storage arrays that include drive arraycontrollers configured to manage read and write access to groups of harddisk drives and/or solid state drives. The drive array controllers,alone or in conjunction with server devices 202, may also be configuredto manage backup or redundant copies of the data stored in data storage204 to protect against drive failures or other types of failures thatprevent one or more of server devices 202 from accessing units ofcluster data storage 204. Other types of memory aside from drives may beused.

Routers 206 may include networking equipment configured to provideinternal and external communications for server cluster 200. Forexample, routers 206 may include one or more packet-switching and/orrouting devices (including switches and/or gateways) configured toprovide (i) network communications between server devices 202 and datastorage 204 via cluster network 208, and/or (ii) network communicationsbetween the server cluster 200 and other devices via communication link210 to network 212.

Additionally, the configuration of cluster routers 206 can be based atleast in part on the data communication requirements of server devices202 and data storage 204, the latency and throughput of the localcluster network 208, the latency, throughput, and cost of communicationlink 210, and/or other factors that may contribute to the cost, speed,fault-tolerance, resiliency, efficiency and/or other design goals of thesystem architecture.

As a possible example, data storage 204 may include any form ofdatabase, such as a structured query language (SQL) database. Varioustypes of data structures may store the information in such a database,including but not limited to tables, arrays, lists, trees, and tuples.Furthermore, any databases in data storage 204 may be monolithic ordistributed across multiple physical devices.

Server devices 202 may be configured to transmit data to and receivedata from cluster data storage 204. This transmission and retrieval maytake the form of SQL queries or other types of database queries, and theoutput of such queries, respectively. Additional text, images, video,and/or audio may be included as well. Furthermore, server devices 202may organize the received data into web page representations. Such arepresentation may take the form of a markup language, such as thehypertext markup language (HTML), the extensible markup language (XML),or some other standardized or proprietary format. Moreover, serverdevices 202 may have the capability of executing various types ofcomputerized scripting languages, such as but not limited to Perl,Python, PHP Hypertext Preprocessor (PHP), Active Server Pages (ASP),JavaScript, and so on. Computer program code written in these languagesmay facilitate the providing of web pages to client devices, as well asclient device interaction with the web pages.

III. EXAMPLE REMOTE NETWORK MANAGEMENT ARCHITECTURE

FIG. 3 depicts a remote network management architecture, in accordancewith example embodiments. This architecture includes three maincomponents, managed network 300, remote network management platform 320,and third-party networks 340, all connected by way of Internet 350.

Managed network 300 may be, for example, an enterprise network used by abusiness for computing and communications tasks, as well as storage ofdata. Thus, managed network 300 may include various client devices 302,server devices 304, routers 306, virtual machines 308, firewall 310,and/or proxy servers 312. Client devices 302 may be embodied bycomputing device 100, server devices 304 may be embodied by computingdevice 100 or server cluster 200, and routers 306 may be any type ofrouter, switch, or gateway.

Virtual machines 308 may be embodied by one or more of computing device100 or server cluster 200. In general, a virtual machine is an emulationof a computing system, and mimics the functionality (e.g., processor,memory, and communication resources) of a physical computer. Onephysical computing system, such as server cluster 200, may support up tothousands of individual virtual machines. In some embodiments, virtualmachines 308 may be managed by a centralized server device orapplication that facilitates allocation of physical computing resourcesto individual virtual machines, as well as performance and errorreporting. Enterprises often employ virtual machines in order toallocate computing resources in an efficient, as needed fashion.Providers of virtualized computing systems include VMWARE® andMICROSOFT®.

Firewall 310 may be one or more specialized routers or server devicesthat protect managed network 300 from unauthorized attempts to accessthe devices, applications, and services therein, while allowingauthorized communication that is initiated from managed network 300.Firewall 310 may also provide intrusion detection, web filtering, virusscanning, application-layer gateways, and other applications orservices. In some embodiments not shown in FIG. 3, managed network 300may include one or more virtual private network (VPN) gateways withwhich it communicates with remote network management platform 320 (seebelow).

Managed network 300 may also include one or more proxy servers 312. Anembodiment of proxy servers 312 may be a server device that facilitatescommunication and movement of data between managed network 300, remotenetwork management platform 320, and third-party networks 340. Inparticular, proxy servers 312 may be able to establish and maintainsecure communication sessions with one or more computational instancesof remote network management platform 320. By way of such a session,remote network management platform 320 may be able to discover andmanage aspects of the architecture and configuration of managed network300 and its components. Possibly with the assistance of proxy servers312, remote network management platform 320 may also be able to discoverand manage aspects of third-party networks 340 that are used by managednetwork 300.

Firewalls, such as firewall 310, typically deny all communicationsessions that are incoming by way of Internet 350, unless such a sessionwas ultimately initiated from behind the firewall (i.e., from a deviceon managed network 300) or the firewall has been explicitly configuredto support the session. By placing proxy servers 312 behind firewall 310(e.g., within managed network 300 and protected by firewall 310), proxyservers 312 may be able to initiate these communication sessions throughfirewall 310. Thus, firewall 310 might not have to be specificallyconfigured to support incoming sessions from remote network managementplatform 320, thereby avoiding potential security risks to managednetwork 300.

In some cases, managed network 300 may consist of a few devices and asmall number of networks. In other deployments, managed network 300 mayspan multiple physical locations and include hundreds of networks andhundreds of thousands of devices. Thus, the architecture depicted inFIG. 3 is capable of scaling up or down by orders of magnitude.

Furthermore, depending on the size, architecture, and connectivity ofmanaged network 300, a varying number of proxy servers 312 may bedeployed therein. For example, each one of proxy servers 312 may beresponsible for communicating with remote network management platform320 regarding a portion of managed network 300. Alternatively oradditionally, sets of two or more proxy servers may be assigned to sucha portion of managed network 300 for purposes of load balancing,redundancy, and/or high availability.

Remote network management platform 320 is a hosted environment thatprovides aPaaS services to users, particularly to the operators ofmanaged network 300. These services may take the form of web-basedportals, for instance. Thus, a user can securely access remote networkmanagement platform 320 from, for instance, client devices 302, orpotentially from a client device outside of managed network 300. By wayof the web-based portals, users may design, test, and deployapplications, generate reports, view analytics, and perform other tasks.

As shown in FIG. 3, remote network management platform 320 includes fourcomputational instances 322, 324, 326, and 328. Each of these instancesmay represent a set of web portals, services, and applications (e.g., awholly-functioning aPaaS system) available to a particular customer. Insome cases, a single customer may use multiple computational instances.For example, managed network 300 may be an enterprise customer of remotenetwork management platform 320, and may use computational instances322, 324, and 326. The reason for providing multiple instances to onecustomer is that the customer may wish to independently develop, test,and deploy its applications and services. Thus, computational instance322 may be dedicated to application development related to managednetwork 300, computational instance 324 may be dedicated to testingthese applications, and computational instance 326 may be dedicated tothe live operation of tested applications and services. A computationalinstance may also be referred to as a hosted instance, a remoteinstance, a customer instance, or by some other designation.

The multi-instance architecture of remote network management platform320 is in contrast to conventional multi-tenant architectures, overwhich multi-instance architectures have several advantages. Inmulti-tenant architectures, data from different customers (e.g.,enterprises) are comingled in a single database. While these customers'data are separate from one another, the separation is enforced by thesoftware that operates the single database. As a consequence, a securitybreach in this system may impact all customers' data, creatingadditional risk, especially for entities subject to governmental,healthcare, and/or financial regulation. Furthermore, any databaseoperations that impact one customer will likely impact all customerssharing that database. Thus, if there is an outage due to hardware orsoftware errors, this outage affects all such customers. Likewise, ifthe database is to be upgraded to meet the needs of one customer, itwill be unavailable to all customers during the upgrade process. Often,such maintenance windows will be long, due to the size of the shareddatabase.

In contrast, the multi-instance architecture provides each customer withits own database in a dedicated computing instance. This preventscomingling of customer data, and allows each instance to beindependently managed. For example, when one customer's instanceexperiences an outage due to errors or an upgrade, other computationalinstances are not impacted. Maintenance down time is limited because thedatabase only contains one customer's data. Further, the simpler designof the multi-instance architecture allows redundant copies of eachcustomer database and instance to be deployed in a geographicallydiverse fashion. This facilitates high availability, where the liveversion of the customer's instance can be moved when faults are detectedor maintenance is being performed.

In order to support multiple computational instances in an efficientfashion, remote network management platform 320 may implement aplurality of these instances on a single hardware platform. For example,when the aPaaS system is implemented on a server cluster such as servercluster 200, it may operate a virtual machine that dedicates varyingamounts of computational, storage, and communication resources toinstances. But full virtualization of server cluster 200 might not benecessary, and other mechanisms may be used to separate instances. Insome examples, each instance may have a dedicated account and one ormore dedicated databases on server cluster 200. Alternatively,computational instance 322 may span multiple physical devices.

In some cases, a single server cluster of remote network managementplatform 320 may support multiple independent enterprises. Furthermore,as described below, remote network management platform 320 may includemultiple server clusters deployed in geographically diverse data centersin order to facilitate load balancing, redundancy, and/or highavailability.

Third-party networks 340 may be remote server devices (e.g., a pluralityof server clusters such as server cluster 200) that can be used foroutsourced computational, data storage, communication, and servicehosting operations. These servers may be virtualized (i.e., the serversmay be virtual machines). Examples of third-party networks 340 mayinclude AMAZON WEB SERVICES® and MICROSOFT® Azure. Like remote networkmanagement platform 320, multiple server clusters supporting third-partynetworks 340 may be deployed at geographically diverse locations forpurposes of load balancing, redundancy, and/or high availability.

Managed network 300 may use one or more of third-party networks 340 todeploy applications and services to its clients and customers. Forinstance, if managed network 300 provides online music streamingservices, third-party networks 340 may store the music files and provideweb interface and streaming capabilities. In this way, the enterprise ofmanaged network 300 does not have to build and maintain its own serversfor these operations.

Remote network management platform 320 may include modules thatintegrate with third-party networks 340 to expose virtual machines andmanaged services therein to managed network 300. The modules may allowusers to request virtual resources and provide flexible reporting forthird-party networks 340. In order to establish this functionality, auser from managed network 300 might first establish an account withthird-party networks 340, and request a set of associated resources.Then, the user may enter the account information into the appropriatemodules of remote network management platform 320. These modules maythen automatically discover the manageable resources in the account, andalso provide reports related to usage, performance, and billing.

Internet 350 may represent a portion of the global Internet. However,Internet 350 may alternatively represent a different type of network,such as a private wide-area or local-area packet-switched network.

FIG. 4 further illustrates the communication environment between managednetwork 300 and computational instance 322, and introduces additionalfeatures and alternative embodiments. In FIG. 4, computational instance322 is replicated across data centers 400A and 400B. These data centersmay be geographically distant from one another, perhaps in differentcities or different countries. Each data center includes supportequipment that facilitates communication with managed network 300, aswell as remote users.

In data center 400A, network traffic to and from external devices flowseither through VPN gateway 402A or firewall 404A. VPN gateway 402A maybe peered with VPN gateway 412 of managed network 300 by way of asecurity protocol such as Internet Protocol Security (IPSEC) orTransport Layer Security (TLS). Firewall 404A may be configured to allowaccess from authorized users, such as user 414 and remote user 416, andto deny access to unauthorized users. By way of firewall 404A, theseusers may access computational instance 322, and possibly othercomputational instances. Load balancer 406A may be used to distributetraffic amongst one or more physical or virtual server devices that hostcomputational instance 322. Load balancer 406A may simplify user accessby hiding the internal configuration of data center 400A, (e.g.,computational instance 322) from client devices. For instance, ifcomputational instance 322 includes multiple physical or virtualcomputing devices that share access to multiple databases, load balancer406A may distribute network traffic and processing tasks across thesecomputing devices and databases so that no one computing device ordatabase is significantly busier than the others. In some embodiments,computational instance 322 may include VPN gateway 402A, firewall 404A,and load balancer 406A.

Data center 400B may include its own versions of the components in datacenter 400A. Thus, VPN gateway 402B, firewall 404B, and load balancer406B may perform the same or similar operations as VPN gateway 402A,firewall 404A, and load balancer 406A, respectively. Further, by way ofreal-time or near-real-time database replication and/or otheroperations, computational instance 322 may exist simultaneously in datacenters 400A and 400B.

Data centers 400A and 400B as shown in FIG. 4 may facilitate redundancyand high availability. In the configuration of FIG. 4, data center 400Ais active and data center 400B is passive. Thus, data center 400A isserving all traffic to and from managed network 300, while the versionof computational instance 322 in data center 400B is being updated innear-real-time. Other configurations, such as one in which both datacenters are active, may be supported.

Should data center 400A fail in some fashion or otherwise becomeunavailable to users, data center 400B can take over as the active datacenter. For example, domain name system (DNS) servers that associate adomain name of computational instance 322 with one or more InternetProtocol (IP) addresses of data center 400A may re-associate the domainname with one or more IP addresses of data center 400B. After thisre-association completes (which may take less than one second or severalseconds), users may access computational instance 322 by way of datacenter 400B.

FIG. 4 also illustrates a possible configuration of managed network 300.As noted above, proxy servers 312 and user 414 may access computationalinstance 322 through firewall 310. Proxy servers 312 may also accessconfiguration items 410. In FIG. 4, configuration items 410 may refer toany or all of client devices 302, server devices 304, routers 306, andvirtual machines 308, any applications or services executing thereon, aswell as relationships between devices, applications, and services. Thus,the term “configuration items” may be shorthand for any physical orvirtual device, or any application or service remotely discoverable ormanaged by computational instance 322, or relationships betweendiscovered devices, applications, and services. Configuration items maybe represented in a configuration management database (CMDB) ofcomputational instance 322.

As noted above, VPN gateway 412 may provide a dedicated VPN to VPNgateway 402A. Such a VPN may be helpful when there is a significantamount of traffic between managed network 300 and computational instance322, or security policies otherwise suggest or require use of a VPNbetween these sites. In some embodiments, any device in managed network300 and/or computational instance 322 that directly communicates via theVPN is assigned a public IP address. Other devices in managed network300 and/or computational instance 322 may be assigned private IPaddresses (e.g., IP addresses selected from the 10.0.0.0-10.255.255.255or 192.168.0.0-192.168.255.255 ranges, represented in shorthand assubnets 10.0.0.0/8 and 192.168.0.0/16, respectively).

IV. EXAMPLE DEVICE, APPLICATION, AND SERVICE DISCOVERY

In order for remote network management platform 320 to administer thedevices, applications, and services of managed network 300, remotenetwork management platform 320 may first determine what devices arepresent in managed network 300, the configurations and operationalstatuses of these devices, and the applications and services provided bythe devices, and well as the relationships between discovered devices,applications, and services. As noted above, each device, application,service, and relationship may be referred to as a configuration item.The process of defining configuration items within managed network 300is referred to as discovery, and may be facilitated at least in part byproxy servers 312.

For purpose of the embodiments herein, an “application” may refer to oneor more processes, threads, programs, client modules, server modules, orany other software that executes on a device or group of devices. A“service” may refer to a high-level capability provided by multipleapplications executing on one or more devices working in conjunctionwith one another. For example, a high-level web service may involvemultiple web application server threads executing on one device andaccessing information from a database application that executes onanother device.

FIG. 5A provides a logical depiction of how configuration items can bediscovered, as well as how information related to discoveredconfiguration items can be stored. For sake of simplicity, remotenetwork management platform 320, third-party networks 340, and Internet350 are not shown.

In FIG. 5A, CMDB 500 and task list 502 are stored within computationalinstance 322. Computational instance 322 may transmit discovery commandsto proxy servers 312. In response, proxy servers 312 may transmit probesto various devices, applications, and services in managed network 300.These devices, applications, and services may transmit responses toproxy servers 312, and proxy servers 312 may then provide informationregarding discovered configuration items to CMDB 500 for storagetherein. Configuration items stored in CMDB 500 represent theenvironment of managed network 300.

Task list 502 represents a list of activities that proxy servers 312 areto perform on behalf of computational instance 322. As discovery takesplace, task list 502 is populated. Proxy servers 312 repeatedly querytask list 502, obtain the next task therein, and perform this task untiltask list 502 is empty or another stopping condition has been reached.

To facilitate discovery, proxy servers 312 may be configured withinformation regarding one or more subnets in managed network 300 thatare reachable by way of proxy servers 312. For instance, proxy servers312 may be given the IP address range 192.168.0/24 as a subnet. Then,computational instance 322 may store this information in CMDB 500 andplace tasks in task list 502 for discovery of devices at each of theseaddresses.

FIG. 5A also depicts devices, applications, and services in managednetwork 300 as configuration items 504, 506, 508, 510, and 512. As notedabove, these configuration items represent a set of physical and/orvirtual devices (e.g., client devices, server devices, routers, orvirtual machines), applications executing thereon (e.g., web servers,email servers, databases, or storage arrays), relationshipstherebetween, as well as services that involve multiple individualconfiguration items.

Placing the tasks in task list 502 may trigger or otherwise cause proxyservers 312 to begin discovery. Alternatively or additionally, discoverymay be manually triggered or automatically triggered based on triggeringevents (e.g., discovery may automatically begin once per day at aparticular time).

In general, discovery may proceed in four logical phases: scanning,classification, identification, and exploration. Each phase of discoveryinvolves various types of probe messages being transmitted by proxyservers 312 to one or more devices in managed network 300. The responsesto these probes may be received and processed by proxy servers 312, andrepresentations thereof may be transmitted to CMDB 500. Thus, each phasecan result in more configuration items being discovered and stored inCMDB 500.

In the scanning phase, proxy servers 312 may probe each IP address inthe specified range of IP addresses for open Transmission ControlProtocol (TCP) and/or User Datagram Protocol (UDP) ports to determinethe general type of device. The presence of such open ports at an IPaddress may indicate that a particular application is operating on thedevice that is assigned the IP address, which in turn may identify theoperating system used by the device. For example, if TCP port 135 isopen, then the device is likely executing a WINDOWS® operating system.Similarly, if TCP port 22 is open, then the device is likely executing aUNIX® operating system, such as LINUX®. If UDP port 161 is open, thenthe device may be able to be further identified through the SimpleNetwork Management Protocol (SNMP). Other possibilities exist. Once thepresence of a device at a particular IP address and its open ports havebeen discovered, these configuration items are saved in CMDB 500.

In the classification phase, proxy servers 312 may further probe eachdiscovered device to determine the version of its operating system. Theprobes used for a particular device are based on information gatheredabout the devices during the scanning phase. For example, if a device isfound with TCP port 22 open, a set of UNIX®-specific probes may be used.Likewise, if a device is found with TCP port 135 open, a set ofWINDOWS®-specific probes may be used. For either case, an appropriateset of tasks may be placed in task list 502 for proxy servers 312 tocarry out. These tasks may result in proxy servers 312 logging on, orotherwise accessing information from the particular device. Forinstance, if TCP port 22 is open, proxy servers 312 may be instructed toinitiate a Secure Shell (SSH) connection to the particular device andobtain information about the operating system thereon from particularlocations in the file system. Based on this information, the operatingsystem may be determined. As an example, a UNIX® device with TCP port 22open may be classified as AIX®, HPUX, LINUX®, MACOS®, or SOLARIS®. Thisclassification information may be stored as one or more configurationitems in CMDB 500.

In the identification phase, proxy servers 312 may determine specificdetails about a classified device. The probes used during this phase maybe based on information gathered about the particular devices during theclassification phase. For example, if a device was classified as LINUX®,a set of LINUX®-specific probes may be used. Likewise if a device wasclassified as WINDOWS® 2012, as a set of WINDOWS®-2012-specific probesmay be used. As was the case for the classification phase, anappropriate set of tasks may be placed in task list 502 for proxyservers 312 to carry out. These tasks may result in proxy servers 312reading information from the particular device, such as basicinput/output system (BIOS) information, serial numbers, networkinterface information, media access control address(es) assigned tothese network interface(s), IP address(es) used by the particular deviceand so on. This identification information may be stored as one or moreconfiguration items in CMDB 500.

In the exploration phase, proxy servers 312 may determine furtherdetails about the operational state of a classified device. The probesused during this phase may be based on information gathered about theparticular devices during the classification phase and/or theidentification phase. Again, an appropriate set of tasks may be placedin task list 502 for proxy servers 312 to carry out. These tasks mayresult in proxy servers 312 reading additional information from theparticular device, such as processor information, memory information,lists of running processes (applications), and so on. Once more, thediscovered information may be stored as one or more configuration itemsin CMDB 500.

Running discovery on a network device, such as a router, may utilizeSNMP. Instead of or in addition to determining a list of runningprocesses or other application-related information, discovery maydetermine additional subnets known to the router and the operationalstate of the router's network interfaces (e.g., active, inactive, queuelength, number of packets dropped, etc.). The IP addresses of theadditional subnets may be candidates for further discovery procedures.Thus, discovery may progress iteratively or recursively.

Once discovery completes, a snapshot representation of each discovereddevice, application, and service is available in CMDB 500. For example,after discovery, operating system version, hardware configuration andnetwork configuration details for client devices, server devices, androuters in managed network 300, as well as applications executingthereon, may be stored. This collected information may be presented to auser in various ways to allow the user to view the hardware compositionand operational status of devices, as well as the characteristics ofservices that span multiple devices and applications.

Furthermore, CMDB 500 may include entries regarding dependencies andrelationships between configuration items. More specifically, anapplication that is executing on a particular server device, as well asthe services that rely on this application, may be represented as suchin CMDB 500. For instance, suppose that a database application isexecuting on a server device, and that this database application is usedby a new employee onboarding service as well as a payroll service. Thus,if the server device is taken out of operation for maintenance, it isclear that the employee onboarding service and payroll service will beimpacted. Likewise, the dependencies and relationships betweenconfiguration items may be able to represent the services impacted whena particular router fails.

In general, dependencies and relationships between configuration itemsbe displayed on a web-based interface and represented in a hierarchicalfashion. Thus, adding, changing, or removing such dependencies andrelationships may be accomplished by way of this interface.

Furthermore, users from managed network 300 may develop workflows thatallow certain coordinated activities to take place across multiplediscovered devices. For instance, an IT workflow might allow the user tochange the common administrator password to all discovered LINUX®devices in single operation.

In order for discovery to take place in the manner described above,proxy servers 312, CMDB 500, and/or one or more credential stores may beconfigured with credentials for one or more of the devices to bediscovered. Credentials may include any type of information needed inorder to access the devices. These may include userid/password pairs,certificates, and so on. In some embodiments, these credentials may bestored in encrypted fields of CMDB 500. Proxy servers 312 may containthe decryption key for the credentials so that proxy servers 312 can usethese credentials to log on to or otherwise access devices beingdiscovered.

The discovery process is depicted as a flow chart in FIG. 5B. At block520, the task list in the computational instance is populated, forinstance, with a range of IP addresses. At block 522, the scanning phasetakes place. Thus, the proxy servers probe the IP addresses for devicesusing these IP addresses, and attempt to determine the operating systemsthat are executing on these devices. At block 524, the classificationphase takes place. The proxy servers attempt to determine the operatingsystem version of the discovered devices. At block 526, theidentification phase takes place. The proxy servers attempt to determinethe hardware and/or software configuration of the discovered devices. Atblock 528, the exploration phase takes place. The proxy servers attemptto determine the operational state and applications executing on thediscovered devices. At block 530, further editing of the configurationitems representing the discovered devices and applications may takeplace. This editing may be automated and/or manual in nature.

The blocks represented in FIG. 5B are for purpose of example. Discoverymay be a highly configurable procedure that can have more or fewerphases, and the operations of each phase may vary. In some cases, one ormore phases may be customized, or may otherwise deviate from theexemplary descriptions above.

V. EXAMPLE QUEUE MANAGEMENT

An aspect of discovery, as well as other types of activities involving amanaged network and an associated computational instance, is howcommunication takes place between these entities. In some embodiments,each computational instance may include a queue that temporarily storescommands readable by the proxy servers of the associated managednetwork, as well as responses to these commands provided by the proxyservers for processing by the computational instance.

One possible implementation of such a queue is a database table or afile, both being persistent storage. Alternatively, non-persistentstorage, such as main memory, could be used. Each output record in thequeue may be a self-contained unit of work for the proxy servers toperform. Each result record in the queue may be a result, generated orobtained by the proxy servers, of one of the units of work. The proxyservers may retrieve and insert these records by way of web services,such as the Simple Object Access Protocol (SOAP) or a RepresentationalState Transfer (REST) application programming interface (API). But othermethods of access may be used.

Once the result is stored in the queue, a particular application may betriggered to read the associated result record from the queue (doing somight or might not remove the result record from the queue). Forinstance, if the unit of work is related to a discovery application, thediscovery application may be informed of the presence of a discoveryresult in the queue, and may remove this result from the queue fordiscovery processing. As part of this processing, the CMDB of thecomputational instance may be updated with information in the result orderived from the result. Even if a unit of work or a result is removedfrom a queue, a record of the unit of work may be maintained in thedatabase for purposes of record keeping, debugging, or later review.

FIG. 6A provides an example of this architecture. Managed network 300contains proxy server 312 and host 600, the latter having an IP addressof 192.168.1.100. Computational instance 322 contains queue 602,application 612, and CMDB 500. Queue 602 includes output storage 604(sometimes referred to as an output queue or request queue) and inputstorage 606 (sometimes referred to as an input queue or a result queue).Herein, a “host” may refer to any computing device or system that isdisposed upon a network and assigned an IP address.

Proxy server 312 communicates with queue 602. This may entail proxyserver 312 periodically or from time to time requesting and receiving aunit of work 608 from output storage 604 (if a unit of work isavailable). Unit of work 608 may be placed in output storage 604 byapplication 612, for instance. After processing and/or otherwisecarrying out this unit of work, proxy server 312 may also provide anassociated result 610 to input storage 606. Application 612 may processthis result and store related information in CMDB 500.

As an illustration of this procedure, unit of work 608 may includecommands to “run SSH to 192.168.1.100” and “run uname-sp”. Thesecommands instruct proxy server 312 to open an SSH connection to host 600and invoke “uname-sp” on the command line. The latter command instructshost 600 to identify its operating system and processor version. Thus,result 610 may include the string “Linux i686” if host 600 is runningthe Linux operating system and using an i686 processor. In this manner,computational instance 322 can determine information about the hardwareand software configuration of hosts on managed network 300.

FIG. 6B provides an example of a unit of work (the unit of work depictedin this figure is different from that of FIG. 6A). This example takesthe form of graphical user interface 620, which could be a web page. Togenerate such a web page, computational instance 322 might read the unitof work from output storage 604 without removing it, and present thisinformation in the form of HTML. Nonetheless, the formatting andpresentation of the unit of work can vary.

As shown in FIG. 6B, the unit of work is made up of characteristics622A, 622B, and 622C. The agent field of characteristics 622A identifiesthe proxy server to which the unit of work should be delivered. Theagent may be specified by a character string, DNS name, IP address, orsome other designation.

The topic field identifies the type of command contained within the unitof work. In this case, the topic is an SSH command. Other types ofcommands can include WINDOWS® PowerShell commands, Java DatabaseConnectivity (JDBC) commands, and so on.

The name field identifies the actual command string to be executed. Inthis case, the string is the UNIX shell command “cat/proc/meminfo”,which provides command line output regarding memory configuration andusage of a host. Possible values of the name field may depend upon thevalue of the topic field.

The source field identifies an IP address of the host that is theintended recipient of the unit of work. In this case, the source fieldspecifies 192.168.1.100, the IP address of host 600.

The sequence field identifies a sequence number of the unit of work,which can be used to match the unit of work with an associated result.Sequence numbers can be generated sequentially, randomly, or accordingto some other mechanism so long as the likelihood of two units of workhaving the same sequence number is reasonably low.

Turning to characteristics 622B, the queue field identifies whether theunit of work is output (i.e., queued for retrieval by a proxy server) orinput (i.e., queued for retrieval by an application of the computationalinstance. In this case, queue field species output, which means that theunit of work is output from queue 602, and is either stored in or wasstored in output storage 604.

The state field identifies whether the unit of work has been processed.Thus, the state field may specify that the unit of work is ready (readyfor processing), processing (currently being delivered or having beendelivered to proxy server 312, and computational instance 322 isawaiting a result), or processed (completed and removed from the queue).In FIG. 6B, the state field indicates that the unit of work is ready forprocessing.

The processed field identifies the time at which the processing of theunit of work completed. This indication may be, for example, a timestamp. In this case, the processed field indicates, consistent with thevalue of the state field, that the unit of work has not yet beenprocessed.

The created field identifies the time at which the unit of work wascreated. This indication may be, for example, a time stamp. In thiscase, the created field indicates that the unit of work was created onNov. 26, 2017 at 11:31:33 AM.

Turning to characteristics 622C, the payload field identifies free-formtext that can be used to represent any other pieces of informationneeded or useful to specify the unit of work. In this case, thisinformation is encoded using XML. Still, other formats such asJavaScript Object Notation (JSON) may be used instead or in addition toXML. The payload field of characteristics 622C includes a port parameterwith a value of 22, a probe_name parameter with a value of Linux-memory,and a credential_id with a value represented by a hexadecimal string.The port parameter indicates which destination TCP port number should beused for the SSH connection to IP address 192.168.1.100. The probe_nameparameter specifies a name for the activity carried out by the unit ofwork. The credential_parameter identifies a set of credentials (e.g.,userid and password) that are accessible to proxy server 312 and are tobe used to establish the SSH connection. The payload field may containmore or fewer parameters.

FIG. 6C provides an example result generated by proxy server 312 inresponse to receiving and processing the unit of work illustrated inFIG. 6B. For instance, proxy server 312 may receive the unit of work,responsively log in to host 600 using SSH with the specified port numberand credentials, then run “cat/proc/meminfo” on the command line andreceive the output of this command. This output may be used as theresult of the carrying out the unit of work. In FIG. 6C, the exampleresult takes the form of graphical user interface 630, such as a webpage. Nonetheless, the formatting and presentation of the result cantake the form of various embodiments.

As shown in FIG. 6C, the unit of work is made up of characteristics632A, 632B, and 632C. The agent, topic, name, source, sequence, andcreated fields of characteristics 632A and 632B are identical to thoseof the unit of work depicted in FIG. 6B. However, the queue, state, andprocessed fields take on different values than the unit of work.

The queue field specifies input, which means that the result is input toqueue 602, and is either stored in or was stored in input storage 606.The state field specifies that the unit of work associated with theresult has been processed. The processed field specifies that thisprocessing completed on Nov. 26, 2017 at 11:31:35 AM.

Not unlike the payload field of characteristics 622C, the payload fieldof characteristics 632C identifies free-form text that can be used torepresent any other pieces of information needed or useful to specifythe result. In this case, this information is encoded using XML, butother formats such as JSON may be used instead or in addition to WL. Thepayload field of characteristics 632C includes a listing of how memoryis allocated in host 600. For instance, there are a total of 255776megabytes of memory, of which 6260 megabytes are free, 16996 megabytesare allocated to buffers, 39168 megabytes are used for caching, 42256megabytes are being actively used (e.g., by applications) and so on. Insome embodiments, the list of memory allocations may be longer orshorter.

This result can be read and removed from input storage 606 by anapplication executing on computational instance 322, such as application612. Usually, this application (or a related program) may deposit theunit of work in output storage 604 and then wait for a result to beplaced into input storage 606.

For instance, a discovery application, such as the one described above,may issue a unit of work, then obtain the result and place some of theinformation therein into CMDB 500. Likewise, a service mappingapplication (e.g., an application that attempts to determinehierarchical relationships and dependencies between a set ofinterconnected applications and hosts configured to operate on managednetwork 300) may issue a different unit of work, and then use its resultin a similar fashion. Also, an event management application may issue aunit of work that requests that system health and stability monitoringsoftware tools operating on managed network 300 proactively reportcertain types of events. These events might be, for example, memoryutilization of a device exceeding a pre-determined threshold, a devicebecoming unreachable or unresponsive, an application operating onmanaged network 300 raising an error, and so on. Proxy server 312 mayreceive reports of these events and place representations thereof inqueue 602. In some cases, user-defined applications may also employqueue 602 in a similar fashion.

There are various advantages and disadvantages to the architecture ofFIG. 6A. In general, it is expected that computational instance 322 willhave greater computational resources (e.g., processor and memorycapacity) than managed network 300. Thus, by placing queue 602 withincomputational instance 322 rather than managed network 300, theseresources can be utilized for the processing and management of queue602. This, in turn, allows proxy server 312 (particular, the applicationthereon that carries out proxy server operations) to be simpler andmaintain less state.

By storing the units of work and results of queue 602 in databasetables, this information can be easily backed up. For instance, writesto these database tables may be replicated across two or more physicaldatabases. Then, if one of these databases fails, another of thedatabases can be used in its place with little or no impact on service.

Furthermore, by placing all units of work and results in a single queue(here, output storage 604 and input storage 606 are considered to bepart of the same logical queue, namely queue 602), this single queueserves as a centralized communication dispatch point between one or moreproxy servers on managed network 300 and applications on computationalinstance 322. Therefore, rather than having to learn about andcommunicate directly with each of these applications, proxy server 312may be configured to communicate with computational instance 322 only byway of queue 602. Likewise, each of these applications does not need tobe configured to communicate with one or more proxy servers, and insteadneed only issue units of work and receive results by way of queue 602.

FIG. 7A depicts these characteristics in arrangement 700. In thisarrangement, managed network 300 includes proxy servers 312A and 312B.Computational instance 322 contains queue 602 and hosts applications612A, 612B, and 612C. Both of proxy servers 312A and 312B cancommunicate with applications 612A, 612B, and 612C by way of queue 602.Thus, queue 602 serves as a centralized dispatch point for messagingbetween managed network 300 and computational instance 322.

It is assumed that each unit of work encodes or is associated with arepresentation of the proxy server to which it is intended to bedelivered. Likewise, each result may encode or being associated with theapplication to which it is intended to be delivered. This allowsinformation placed in queue 602 to be properly multiplexed andde-multiplexed.

Despite its advantages, the architecture of FIG. 6A (as depicted inarrangement 700 of FIG. 7A) also has drawbacks and limitations. Oneexample is that there is a maximum size within which results must fit.This size may be 1 megabyte, 5 megabytes, 10 megabytes or some otherquantity. Such a limit is usually necessary to prevent writes and readsof queue 602 from consuming too many resources of computational instance322. As an example, if a 10 gigabyte result were written to queue 602,doing so may slow down the rate at which applications 612A, 612B, and612C can communicate with proxy servers 312A and 312B for severalseconds or more, and/or may lead to software instability. Large units ofwork and results also cause head-of-line blocking, in which one largeentry in a queue takes so long to be removed and/or processed thatentries behind it in the queue are delayed to the point that theirassociated applications are negatively impacted.

Furthermore, when implemented as a single logical queue, queue 602cannot easily facilitate differentiation between of units of work andresults associated with different applications or different priorities.For example, it may be desirable for event management applicationsoperating on computational instance 322 to receive events as quickly aspossible, while discovery and service mapping applications operating oncomputational instance 322 might not exhibit the same urgency. But,high-priority results may be placed behind lower priority results inqueue 602, causing these high priority results to be delayed and furthercausing potential degradations in system performance.

Additionally, some types of applications that use queue 602 mightgenerate redundant results or new results that override or duplicatepreviously-queued results. For instance, discovery procedures, if notconfigured properly, could “discover” the same computing devices morethan once. Therefore, devices may be represented in multiple entries inqueue 602. Similarly, event management applications might reportmultiple events representing the same state of a computing device. As anexample, system health and stability monitoring software tools operatingon managed network 300 might periodically report (e.g., every fewseconds) when a parameter of a computing device (e.g., memoryutilization or processor utilization) on managed network 300 is out ofrange. Therefore, there may be multiple events in queue 602 containingthis information.

VI. IMPROVED QUEUE MANAGEMENT

The embodiments herein generalize the single-queue approach depicted inFIGS. 6A and 7A to a multiple-queue approach that addresses theaforementioned problems. There are several possible ways of determininghow many queues should be used, and which units of work (and theircorresponding results) should be assigned to each queue. FIGS. 7B-7Dexplore some of these possibilities.

Arrangement 702 of FIG. 7B involves queue 602 of FIG. 7A being replacedby two queues, namely queues 602A and 602B. These queues arerespectively dedicated to a particular proxy server. Thus, queue 602A isdedicated to proxy server 312A and queue 602B is dedicated to proxyserver 312B. Arrangement 702 is a simplified example of an architecturein which n queues are respectively dedicated to n proxy servers, where nis at least 2.

On the other hand, each of applications 612A, 612B, and 612C isconfigured to communicate with managed network 300 by way of both ofqueues 602A and 602B. Thus, for example, application 612A may issue, toqueue 602A, units of work that are to be carried out by proxy server312A. Application 612A may also issue, to queue 602B, units of work thatare to be carried out by proxy server 312B. Proxy server 312A, in turn,only retrieves units of work from queue 602A and writes associatedresults thereto, and proxy server 312B only retrieves units of work fromqueue 602B and write associated results thereto.

Arrangement 702 generally requires applications 612A, 612B, and 612C tobe configured in advance with regard to the capabilities of proxyservers 312A and 312B, proxy server IP addresses and/or subnets, andpossibly other criteria, so that the applications can determine in whichqueue a particular unit of work should be placed in order to be carriedout by the appropriate proxy server. However, if proxy servers 312A and312B are located in geographically or topologically different areas,such a configuration would naturally result from the distributed networkarchitecture. Alternatively, if proxy server 312A and proxy server 312Bare co-located, the applications may place units of work in eitherqueue. Doing so may serve to balance load across the queues and acrossthe proxy servers.

In general, arrangement 702 provides a way of reducing the bottlenecksand other drawbacks of a single-queue arrangement. Some head-of-lineblocking may be mitigated, causing faster overall delivery of results.

Arrangement 704 of FIG. 7C involves queue 602 of FIG. 7A being replacedby three queues, namely queues 602A, 602B, and 602C. These queues arerespectively dedicated to a particular application. Thus, queue 602A isdedicated to application 612A, queue 602B is dedicated to application612B, and queue 602C is dedicated to application 612C. Arrangement 704is a simplified example of an architecture in which n queues arerespectively dedicated to n applications, where n is at least 2.

On the other hand, each of proxy servers 312A and 312B is configured tocommunicate with computational instance 322 by way of each of queues602A, 602B, and 602C. Thus, for example, application 612A may issue, toqueue 602A, units of work that are to be carried out by proxy server312A. Application 612B may issue, to queue 602B, units of work that arealso to be carried out by proxy server 312A. Proxy server 312A, in turn,retrieves units of work from both queues 602A and 602B, and writesassociated results back to these respective queues.

Arrangement 704 generally requires that both of proxy servers 312A and312B are configured to check each of queues 602A, 602B, and 602C at theappropriate frequency. This may result in some extent of additionaloperations being carried out by the proxy servers. On the other hand,the applications only need to be configured to communicate by way of asingle queue.

Like arrangement 702, arrangement 704 provides a way of reducing thebottlenecks and other drawbacks of a single-queue arrangement. Somehead-of-line blocking may be mitigated, causing faster overall deliveryof results. Furthermore, arrangement 704 logically associates queueswith applications, so that applications that are delay-sensitive (e.g.,event management) are less impacted by applications that are notdelay-sensitive (e.g., discovery). In other words, event managementresults are not unduly delayed by being queued behind discovery results.Therefore, arrangement 704 may be used as a de facto per-applicationprioritization mechanism.

Arrangement 706 of FIG. 7D provides a more general prioritizationmechanism. Queue 602A is dedicated to high-priority (priority 1) unitsof work and their associated results, while queue 602B is dedicated tolow-priority (priority 2) units of work and their associated results.Both of proxy servers 312A and 312B, as well as all of applications612A, 612B, and 612C, may use either queue. Arrangement 706 is asimplified example of an architecture in which n queues are respectivelydedicated to n priority levels, where n is at least 2.

For each unit of work generated by an application, the applicationdetermines its relative priority, and then places the unit of work in anappropriate queue. While some applications may assign the same priorityto all of the units of work that they generate, others may generateunits of work with varying priorities. For example, an event managementapplication may manage events of varying criticalities, and maydetermine how to queue the associated units of work accordingly.

While arrangement 706 is somewhat more complex than arrangements 702 and704, in that all proxy servers and applications may be configured to useall of the queues, it is also more flexible. Head of line blocking andbottlenecks may be mitigated or eliminated by having enough queues andassigning units of work to these queues appropriately.

While each have their respective advantages, none of arrangements 702,704, or 706 specifically address the aforementioned issues related tothe size limit of units of work and redundant results. Arrangement 708of FIG. 7E can be used to resolve these issues.

Unlike arrangements 700, 702, 704, and 706, arrangement 708 focuses onmodifications to proxy server 312. Thus, arrangement 708 may be used inconjunction with these other arrangements, as an optional feature forany. Therefore, while FIG. 7E only depicts one queue (queue 602) incomputational instance 322, any number of queues may be present andproxy server 312 may be configured to communicate by way of one or moreof these queues.

As depicted, proxy server 312 includes proxy queue 710 and proxy queuemanager 712. Proxy queue manager 712 may be a software application formanaging proxy queue 710. Proxy queue 710 may be used to store resultsthat are intended to be placed in queue 602 (more specifically, inputstorage 606). Thus, proxy queue includes a head and a tail, and proxyqueue manager writes incoming results to the tail and reads outgoingresults from the head, placing these read results into queue 602.

At any point in time, proxy queue 710 may include one or more results.In FIG. 7E, these results are encoded by requesting application andnumber. Thus, proxy queue 710 includes three results for application X(results X1, X2, and X3), as well as one result for application Y (Y1)and one result for application Z (Z1).

Particularly, proxy queue manager 712 may hold some results in proxyqueue 710 for a period of time (e.g., a few seconds). This may allowother results associated with the same application to accumulate inproxy queue 710. Then, proxy queue manager 712 may examine these queuedresults to determine whether any can be combined or removed.

For example, results X1, X2, and X3 are all intended to be provided toapplication X. In some cases, results X2 and X3 may be redundant copiesof the same information that is in result X1. In this case, proxy queuemanager 712 may delete results X2 and X3 (or results X1 and X2) fromproxy queue 710, thereby reducing the load on the system and theprocessing required to deliver results to application X. Alternatively,results X2 and X3 (or results X1 and X2) may be merged together if theyare at least partially overlapping.

Alternatively or additionally, proxy queue manager 712 may determine ifany of the queued results exceed the size limit of queue 602. If that isthe case, proxy queue manager 712 may remove the result from proxy queue710, split the result into two or more separate results, and then placeeach of these separate results in proxy queue 710. For instance, if alarge result is in the form of an XML, or JSON file, proxy queue manager712 might split this one file into two or more separate, syntacticallycorrect XML or JSON files. Doing so may allow computational instance 322to process these files in parallel if multiple worker threads aresupported.

In this fashion, both result redundancy and result size limit issues canbe addressed appropriately. Nonetheless, arrangement 708 does add stateand complexity to proxy server 312. As a consequence, it may bebeneficial to store proxy queue 710 as a table in a redundant database,or use some other form of high availability mechanism to mitigate dataloss if proxy server 312 crashes, becomes unresponsive, or otherwisefails.

VII. EXAMPLE OPERATIONS

FIG. 8 is a flow chart illustrating an example embodiment. The processillustrated by FIG. 8 may be carried out by a computing device, such ascomputing device 100, and/or a cluster of computing devices, such asserver cluster 200. However, the process can be carried out by othertypes of devices or device subsystems. For example, the process could becarried out by a portable computer, such as a laptop or a tablet device.

The embodiments of FIG. 8 may be simplified by the removal of any one ormore of the features shown therein. Further, these embodiments may becombined with features, aspects, and/or implementations of any of theprevious figures or otherwise described herein.

Block 800 may involve selecting, by a particular application of aplurality of applications, a particular request (output) queue of aplurality of queues. A computational instance disposed within a remotenetwork management platform may contain the plurality of queues andfacilitate execution of the plurality of applications. Each of theplurality of applications may be configured to communicate, by way ofone or more of the plurality of queues, with one or more of a pluralityof proxy server applications disposed within a managed network. Theremote network management platform may manage the managed network by wayof the computational instance.

Block 802 may involve writing, by the particular application, a unit ofwork generated by the particular application to a particular request(output) queue of the plurality of queues.

Block 804 may involve retrieving, by a particular proxy serverapplication of the plurality of proxy server applications, the unit ofwork from the particular request (output) queue.

Block 806 may involve carrying out, by the particular proxy serverapplication, the unit of work.

Block 808 may involve writing, by the particular proxy serverapplication, a result to a particular result (input) queue of theplurality of queues. The result may represent an outcome of carrying outthe unit of work. The particular result (input) queue may be associatedwith the particular request (output) queue.

Block 810 may involve retrieving, by the particular application, theresult from the particular result (input) queue.

Some embodiments may involve a one-to-one relationship between the proxyserver applications and the queues. Each of the plurality of proxyserver applications may use a respectively dedicated queue (e.g., pairedrequest (output) and result (input) queues) of the plurality of queuesto communicate with the plurality of applications.

Some embodiments may involve a one-to-one relationship between theapplications and the queues. Each of the plurality of applications mayuse a respectively dedicated queue (e.g., paired request (output) andresult (input) queues) of the plurality of queues to communicate withthe plurality of proxy server applications.

In some embodiments, each of the plurality of queues is associated witha different priority. Writing the unit of work generated by theparticular application in the particular request (output) queue may bebased on matching a priority of the unit of work with the priorityassociated with the particular request (output) queue. A time at whichthe particular proxy server application retrieves the unit of work fromthe particular request (output) queue may be based on the priorityassociated with the particular request (output) queue.

In some embodiments, the particular proxy server application contains:(i) a proxy queue configured to store results to be placed in theparticular result (input) queue, the proxy queue including a head and atail, and (ii) a proxy queue manager configured to write incomingresults to the tail, read outgoing results from the head, and place readresults in the particular result (input) queue. The proxy queue managermay be configured to detect duplicate results in the proxy queue, and toremove all but one of the duplicate results from the proxy queue. Theproxy queue manager may be configured to detect partially-overlappingresults in the proxy queue, and to merge the partially-overlappingresults into a smaller number of results. The proxy queue manager may beconfigured to hold the result in the proxy queue beyond a nominal timeat which the result would otherwise be read, and combine the result withone or more other results that arrived to the proxy queue at a latertime. The proxy queue manager may be configured to detect that theresult exceeds a predetermined size limit, and split the result into twoor more results that do not exceed the predetermined size limit.

VIII. CONCLUSION

The present disclosure is not to be limited in terms of the particularembodiments described in this application, which are intended asillustrations of various aspects. Many modifications and variations canbe made without departing from its scope, as will be apparent to thoseskilled in the art. Functionally equivalent methods and apparatuseswithin the scope of the disclosure, in addition to those describedherein, will be apparent to those skilled in the art from the foregoingdescriptions. Such modifications and variations are intended to fallwithin the scope of the appended claims.

The above detailed description describes various features and operationsof the disclosed systems, devices, and methods with reference to theaccompanying figures. The example embodiments described herein and inthe figures are not meant to be limiting. Other embodiments can beutilized, and other changes can be made, without departing from thescope of the subject matter presented herein. It will be readilyunderstood that the aspects of the present disclosure, as generallydescribed herein, and illustrated in the figures, can be arranged,substituted, combined, separated, and designed in a wide variety ofdifferent configurations.

With respect to any or all of the message flow diagrams, scenarios, andflow charts in the figures and as discussed herein, each step, block,and/or communication can represent a processing of information and/or atransmission of information in accordance with example embodiments.Alternative embodiments are included within the scope of these exampleembodiments. In these alternative embodiments, for example, operationsdescribed as steps, blocks, transmissions, communications, requests,responses, and/or messages can be executed out of order from that shownor discussed, including substantially concurrently or in reverse order,depending on the functionality involved. Further, more or fewer blocksand/or operations can be used with any of the message flow diagrams,scenarios, and flow charts discussed herein, and these message flowdiagrams, scenarios, and flow charts can be combined with one another,in part or in whole.

A step or block that represents a processing of information cancorrespond to circuitry that can be configured to perform the specificlogical functions of a herein-described method or technique.Alternatively or additionally, a step or block that represents aprocessing of information can correspond to a module, a segment, or aportion of program code (including related data). The program code caninclude one or more instructions executable by a processor forimplementing specific logical operations or actions in the method ortechnique. The program code and/or related data can be stored on anytype of computer readable medium such as a storage device including RAM,a disk drive, a solid state drive, or another storage medium.

The computer readable medium can also include non-transitory computerreadable media such as computer readable media that store data for shortperiods of time like register memory and processor cache. The computerreadable media can further include non-transitory computer readablemedia that store program code and/or data for longer periods of time.Thus, the computer readable media may include secondary or persistentlong term storage, like ROM, optical or magnetic disks, solid statedrives, compact-disc read only memory (CD-ROM), for example. Thecomputer readable media can also be any other volatile or non-volatilestorage systems. A computer readable medium can be considered a computerreadable storage medium, for example, or a tangible storage device.

Moreover, a step or block that represents one or more informationtransmissions can correspond to information transmissions betweensoftware and/or hardware modules in the same physical device. However,other information transmissions can be between software modules and/orhardware modules in different physical devices.

The particular arrangements shown in the figures should not be viewed aslimiting. It should be understood that other embodiments can includemore or less of each element shown in a given figure. Further, some ofthe illustrated elements can be combined or omitted. Yet further, anexample embodiment can include elements that are not illustrated in thefigures.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments will be apparent to those skilled in the art.The various aspects and embodiments disclosed herein are for purpose ofillustration and are not intended to be limiting, with the true scopebeing indicated by the following claims.

What is claimed is:
 1. A system comprising: one or more first servercomputing devices disposed within a managed network and configured torun a plurality of proxy server applications; and one or more secondserver computing devices configured to host a computational instancedisposed within a remote network management platform, wherein the remotenetwork management platform manages the managed network by way of thecomputational instance, wherein the computational instance contains aplurality of queues and facilitates execution of a plurality ofapplications, wherein each of the plurality of applications isconfigured to communicate with one or more of the proxy serverapplications by way of one or more of the plurality of queues, thecommunication comprising operations of: selecting, by a particularapplication of the plurality of applications, a particular output queueof the plurality of queues; writing, by the particular application, aunit of work generated by the particular application to the particularoutput queue; retrieving, by a particular proxy server application ofthe plurality of proxy server applications, the unit of work from theparticular output queue; carrying out, by the particular proxy serverapplication, the unit of work; writing, by the particular proxy serverapplication, a result to a particular input queue of the plurality ofqueues, wherein the result represents an outcome of carrying out theunit of work, and wherein the particular input queue is associated withthe particular output queue; and retrieving, by the particularapplication, the result from the particular input queue; wherein themanaged network comprises: a proxy queue configured to store results tobe placed in the particular input queue, the proxy queue including ahead and a tail; and a proxy queue manager configured to: write incomingresults to the tail, read outgoing results from the head, and place readresults in the particular input queue; and hold the result in the proxyqueue beyond a nominal time at which the result would otherwise be read,and combine the result with one or more other results that arrived tothe proxy queue at a later time.
 2. The system of claim 1, wherein thereis a one-to-one relationship between the proxy server applications andthe queues.
 3. The system of claim 2, wherein each of the plurality ofproxy server applications uses a respectively dedicated queue of theplurality of queues to communicate with the plurality of applications.4. The system of claim 1, wherein there is a one-to-one relationshipbetween the applications and the queues.
 5. The system of claim 4,wherein each of the plurality of applications uses a respectivelydedicated queue of the plurality of queues to communicate with theplurality of proxy server applications.
 6. The system of claim 1,wherein each of the plurality of queues is associated with a differentpriority, and wherein writing the unit of work generated by theparticular application in the particular output queue is based onmatching a priority of the unit of work with the priority associatedwith the particular output queue.
 7. The system of claim 6, wherein atime at which the particular proxy server application retrieves the unitof work from the particular output queue is based on the priorityassociated with the particular output queue.
 8. The system of claim 1,wherein the proxy queue manager is configured to detect duplicateresults in the proxy queue, and to remove all but one of the duplicateresults from the proxy queue.
 9. The system of claim 1, wherein theproxy queue manager is configured to detect partially-overlappingresults in the proxy queue, and to merge the partially-overlappingresults into a smaller number of results.
 10. The system of claim 1,wherein the proxy queue manager is configured to detect that the resultexceeds a predetermined size limit, and split the result into two ormore results that do not exceed the predetermined size limit.
 11. Amethod comprising: selecting, by a particular application of a pluralityof applications, a particular output queue of a plurality of queues,wherein a computational instance disposed within a remote networkmanagement platform contains the plurality of queues and facilitatesexecution of the plurality of applications, wherein each of theplurality of applications is configured to communicate, by way of one ormore of the plurality of queues, with one or more of a plurality ofproxy server applications disposed within a managed network, wherein theremote network management platform manages the managed network by way ofthe computational instance; writing, by the particular application, aunit of work generated by the particular application to a particularoutput queue of the plurality of queues; retrieving, by a particularproxy server application of the plurality of proxy server applications,the unit of work from the particular output queue; carrying out, by theparticular proxy server application, the unit of work; writing, by theparticular proxy server application, a result to a particular inputqueue of the plurality of queues, wherein the result represents anoutcome of carrying out the unit of work, and wherein the particularinput queue is associated with the particular output queue; andretrieving, by the particular application, the result from theparticular input queue; wherein the managed network comprises: a proxyqueue configured, wherein the proxy queue includes a head and a tail;and a proxy queue manager configured to: write incoming results to thetail, read outgoing results from the head, and place read results in theparticular input queue; and hold the result in the proxy queue beyond anominal time at which the result would otherwise be read, and combinethe result with one or more other results that arrived to the proxyqueue at a later time.
 12. The method of claim 11, wherein there is aone-to-one relationship between the proxy server applications and thequeues.
 13. The method of claim 11, wherein there is a one-to-onerelationship between the applications and the queues.
 14. The method ofclaim 11, further comprising: detecting, by the proxy queue manager,duplicate results in the proxy queue; and removing, by the proxy queuemanager, all but one of the duplicate results from the proxy queue. 15.The method of claim 11, further comprising: detecting, by the proxyqueue manager, partially-overlapping results in the proxy queue; andmerging, by the proxy queue manager, the partially-overlapping resultsinto a smaller number of results.